Referring to FIGS. 1 to 3, a conventional vehicle taillight 1 includes a housing 11, and two brake light emitting devices 12 and a reverse light emitting device 13 mounted in the housing 11 and arranged in a top-bottom direction. Each brake light emitting device 12 includes a base 121, a circuit board 122 disposed inside the base 121, a plurality of light emitting members 123 disposed on the circuit board 122 and arranged in a U-shape, a light guide seat 124 disposed in the base 121 and located rearwardly of the light emitting members 123, a reflective plate 125 disposed inside the light guide seat 124, a frame 126 engagingly disposed in the light guide seat 124, and a light transmitting plate 127 disposed inside the frame 126 and rearwardly spaced from the reflective plate 125. The light emitting members 123 are light emitting diodes, and different power are used to produce two shades of light with the same color but different intensities. The light transmitting plate 127 is made of a semi-reflective material to allow a portion of light to pass therethrough and the other portion of the light to reflect onto the reflective plate 125.
When the vehicle taillight 1 is located in a normal driving mode, the light emitting members 123 will emit a low-power colored light (such as red). The colored light enters the light guide seat 124, projects onto the frame 126, and then reflects onto the light transmitting plate 127. At this time, a portion of the light directly penetrates the light transmitting plate 127, while the other portion of the light is reflected by the light transmitting plate 127 onto the reflective plate 125. From the reflective plate 125, the light is again reflected onto the light transmitting plate 127, thereby resulting in gradual change of light. When the vehicle taillight 1 is shifted to a braking mode, the light emitting members 123 will emit a high-power colored light, the projecting method of which is similar to that of the low-power colored light.
Although the brake light emitting devices 12 of the conventional vehicle taillight 1 have a driving signal and a brake signal effects, the housing 11 of the conventional vehicle taillight 1 must be assembled with the reverse light emitting device 13 therein to further have a reverse signal effect. This kind of design is not only bulky and occupies space, but also increases the difficult allocation of an internal space of the housing 11.